I have not tried it and would not due to concerns about hybridization and fighting. Also I like a little more contrast in my tank, they look too similar to me. Finally cobue have a rep for having trouble coloring up unless they are dominant and kingsizei have a rep for being aggressive.
Maybe there is someone out there who HAS actually tried it with success for 1-2 years. opcorn:
Depends on whose tougher. Kingsizei as in metriaclima pupican? http://www.cichlid-forum.com/profiles/species.php?id=894 if you have a cave on opposite ends of the tank for them to claim as their own, the should be fine. my cobue male used to ignore the pupican females and vice versa. Couldn't say the same for both of the males. The middle of the tank was the beginning and ending of their territories. Good luck!
i have two seperate rock piles and in between i put a terra cotta pot to try to break up the line of sight. I am gonna buy as 1-2 inch juvies. i am hoping aggression wont b an issue for a little while until i can get a seperate tank set up. i like the looks of both and thought the males looked different enough